Now the new corona virus 2019-nCoV has also appeared in Germany. The health systems are well prepared for this. In the country of origin China, however, thousands are infected and it is still uncertain how dangerous the pathogen is. There are no medicines to treat the sick. Rolf Hilgenfeld tries to help. The biochemist has been traveling in China since last week.
ZEIT ONLINE: Mr. Hilgenfeld, what are you currently doing specifically?
Rolf Hilgenfeld: I want to find out whether the inhibitors we developed at the University of Lübeck are against the new one coronavirus work as well as against Sars and Mers viruses. I'm looking for cooperation partners who have cell cultures with the new virus that they can use to test the substances. However, our substances are still in an experimental stage. Unfortunately, they are still far from being able to be used as a medicine in the current outbreak.
ZEIT ONLINE: There is still no medicine for the new one virus?
Hilgenfeld: No, not yet approved, because 2019-nCoV has only just been discovered. But the Sars outbreak in 2002 and 2003 has had various experiences drugs made. And a combination product consisting of two substances proved to be particularly promising in the first clinical tests: the combination of the active ingredients lopinavir and ritonavir. These are actually medicines for HIV.
ZEIT ONLINE: You say Coronavirus patients should be given AIDS drugs?
Hilgenfeld: That's the way it is. Especially in outbreak situations like now, people regularly try to rededicate drugs that have already been approved. This has the advantage that these agents have already been extensively tested on humans and can therefore be considered safe. This can save you years of testing, because if there is an outbreak, time is usually short. Developing something new now takes far too long. And lopinavir and ritonavir are approved – just against HIV.
ZEIT ONLINE: How do these drugs work?
Hilgenfeld: To multiply, RNA viruses – like 2019-nCoV – initially form very large protein molecules. Then certain enzymes have to cut them into individual components so that the virus can multiply. That is exactly what you want to prevent. You can do this by inhibiting the enzymes. The good thing is: these enzymes are very similar in the individual corona viruses. We researched this in Lübeck before the Sars outbreak in 2002. At that time, corona viruses were still considered unimportant for humans. It was thought that they only trigger colds. At that time, many even advised me to stop doing this "unimportant" work. And when the Sars pandemic began shortly afterwards, we were the only ones who had ever uncovered three-dimensional structures of coronavirus proteins. On that basis, we developed a substance that could be used to inhibit corona viruses. We were able to suggest that a drug that was supposed to work against rhinoviruses – the typical "runny nose virus" – should also be effective against coronaviruses after slight changes.
ZEIT ONLINE: If so, why can't you use the substance in the current outbreak?
Hilgenfeld: It is still in an experimental state. To use it, it has to be developed into a drug over many years of research. When we wanted to do more testing back then, the Sars outbreak was over and we didn't have any patients to test the substance on. This is also a basic problem in all research in this area.
ZEIT ONLINE: What do you mean?
Hilgenfeld: First you have to show in an animal experiment that a substance is safe – and then that it works. But you can't just infect a mouse with coronaviruses, you have to plant a human receptor in the mouse – you have to "humanize" it. It takes months. And only then do the examinations on patients begin, which take years to complete. And when you are finally there, there will be no more sick people to test the remedies because the outbreak is over. For this reason it is difficult to find funding. And the pharmaceutical industry is not interested in corona viruses. Even the 8,000 Sars cases at that time are not a lucrative market for companies. This is another reason why we now have no effective medication against the new virus.
ZEIT ONLINE: Viruses change their genetic makeup when they reproduce. Does that make it so difficult to develop an effective drug?